What is a compound Interest Calculator?
Compound interest is what actually drives most real investment and loan growth — each period’s interest is added to the principal, so the next period earns interest on a larger base. This is what people mean by "compounding," and it’s the same underlying maths behind FDs, PPF, lumpsum mutual fund investments, and reducing-balance loans.
Enter the principal, rate, time period and how often interest compounds to see the total value and interest earned.
How compound interest is calculated
P is principal, r is the annual rate, k is the number of times interest compounds per year (1 for annual, 4 for quarterly, 12 for monthly), and t is time in years. Higher compounding frequency gives a marginally higher return for the same stated annual rate.
Frequently asked questions
Why does compounding frequency matter if the rate is the same?
More frequent compounding means interest starts earning its own interest sooner within each year — a 10% rate compounded monthly yields slightly more over a year than the same 10% compounded annually, even though the stated rate is identical.
What’s the difference between this and the FD Calculator?
They use the same underlying maths — the FD Calculator is this same formula, pre-set to the compounding conventions and typical rate ranges of Indian bank fixed deposits.
Does compound interest apply to loans too?
Yes — a reducing-balance loan (like most bank loans) charges compound interest on the outstanding balance each period, which is exactly what the EMI Calculator models.